Noun:

డెడ్ మెయిల్,

dead mail's Usage Examples:

readily returned, including mail without a return address, is treated as dead mail at a Mail Recovery Center in Atlanta, Georgia or Saint Paul, Minnesota.

With this rise in dead mail, the post office pleaded for people to use a return address.

The term "dead mail" is perhaps a misnomer, and several jurisdictions have opted for the use.

Synonyms:

pulseless, departed, exsanguinous, late, fallen, d.o.a., doomed, exsanguine, nonviable, stone-dead, murdered, assassinated, inanimate, slain, executed, at rest, breathless, deceased, lifeless, brain dead, gone, stillborn, life, asleep, exanimate, vitality, deathly, bloodless, animation, cold, living, deathlike, aliveness, at peace, defunct,

Antonyms:

alive, early, middle, punctual, up,